Quality control and detection limit sensitivities in small instrument systems are subject to full flow volumes and accurate assessment of analytes in fluid samples. Accurate sensitivity values depend on accurate and consistent fluid volumes. As such, any variation in fluid volume has a large effect on sensitivities reported for various sample analyses. Leaks in valves and valve systems of bench-scale analytical instruments can occur when, e.g., valve seals fail, or when incorrect fluid volumes are delivered within analytical process flows. Early detection of such leaks can limit quality control consequences and incorrect reporting of analytical results stemming from failed valves and valve systems in these instruments. Accordingly, new leak detection systems, devices, and methods are needed that permit early detection of fluid leaks in analytical instruments that reduce the quantity of failed samples.